1. Field of the Invention
The present invention relates to a process for making a pattern on fabric, such as cloth and clothing, dyed with a colorant or a dye through decolorizing, discoloring, or bleaching. And more particularly, it relates to a process for easily producing an intended pattern on dyed fabric or colored clothing, particularly denim clothing such as Jeans. The invention also relates to an apparatus using in the process. Further, the invention also relates to dyed fabric having a pattern and colored clothing having a pattern that are produced by the process.
2. Description of the Related Art
As one of techniques for improving the fashion value of textile products, such a method has been carried out that a part of dyed cloth or clothing is decolorizing to make a pattern. In particular, because there is a tendency in denim clothing that partially decolorized products have the preference, processing technology for making a pattern has been particularly advanced, and various processes have been proposed. For example, a stone wash method and a sand blast method of applying physical impacts to fabric, and a chemical wash method of chemically decomposing the dye by using a reagent, such as sodium hypochlorite, have been industrially and widely used as general methods.
While these methods are effective as a process for decolorizing the whole or a wide area of denim clothing, it is very difficult to make an intended pattern of figures and letters on a specified part thereof, and a large-sized equipment is required. A printing method has been used for making an intended pattern. In this method, a pattern mold shaped in a negative image of the intended pattern is plated on dyed fabric, and a paste containing a reagent, such as sodium hypochlorite, is then printed thereon, whereby a dye on the part where the paste is attached is decolorized to make the pattern.
Other examples of the method for making an intended pattern of figures and letters on denim clothing include a method using a laser (Japanese Patent Laid-Open No. 102386/1998) and a method, in which dyed fabric is further dyed with a mordant dye, and then the mordant dye on an intended part is discharged (Japanese Patent Laid-Open No. 13287/1997). What are disclosed with respect to dyed cloth include a method, in which a pattern mold is placed on dyed fabric, and particles are blown thereon (Japanese Patent Laid-Open No. 17381/1994), a method using an ultraviolet ray (Japanese Patent Laid-Open No. 207386/1994), a method using ozone (Japanese Patent No. 2,864,110 or Japanese Patent Laid-open No. 228266/1997) and a method using microorganisms (Japanese Patent Laid-Open No. 97785/1995).
However, the conventional methods for making an intended pattern of figures and letters have the following problems. In the printing method, which is a decolorizing method by application of a paste, it is necessary that the paste is dried after application and is finally removed. It also requires complicated processing steps, for example, steaming is necessarily carried out on the decolorizing step. Furthermore, since water is used to remove the paste, such a problem arises that a large amount of wastewater containing the paste is formed.
The foregoing methods for solving the problems of the printing method also have problems. In the methods using a laser or an ultraviolet ray, a large-sized equipment is required for irradiation of light, and there is a possibility that safety of the working environment is jeopardized by irradiation of a laser light beam or an ultraviolet ray. In the method where a mordant dye is discharged, such a step is required that dyed cloth or clothing is further dyed with a mordant dye, and thus complicated operation is necessarily added as a method for making a pattern. In the method using particles, fibers of the fabric are liable to be damaged, and there is a possibility of deterioration of the working environment due to flying of powder caused by blowing particles. In the method using ozone, such considerably complicated equipment and operations are required that the processing is necessarily carried out in an airtight vessel due to the use of harmful ozone, and an equipment for removing remaining ozone is necessary. In the method using microorganisms, such considerably complicated operations requiring a long period of time are necessary that the operations are necessarily carried out under temperature conditions, at which the microorganisms are grown, and the operations take several hours.
Upon considering the diversification of demands of the consumer, such a process is demanded that can easily and quickly make a pattern, but most of the processes having been proposed are those requiring particular processing steps or equipments for decolorizing, and thus no simple process has been practiced.
As a result of earnest investigations made by the inventors taking the foregoing problems into consideration, the invention has been completed. An object of the invention is to provide a process for intentionally making a pattern of figures and letters by decolorizing dyed cloth or clothing in a short period of time without forming a large amount of waste water, without causing deterioration of the working environment, and without using any further particular processing step or processing equipment.
The invention relates to a process for producing a pattern on dyed fabric by decolorization, discoloration or change of color (which is sometimes simply referred to as bleaching). Specifically, the invention relates to a process for making a pattern on dyed fabric containing the steps of: impregnating dyed fabric with a substance forming an oxidized active species upon electrolysis (hereinafter, the substance is sometimes referred to as an electron carrier); inserting the dyed fabric between a pair of electrodes; and applying electricity to the electrodes, whereby only a part of the dyed fabric where electricity is applied is selectively subjected to decolorization, discoloration or change of color.
In a part where no electricity is applied, no oxidized active species is formed from the electron carrier. Therefore, a pattern of figures and letters can be arbitrarily made by specifying the part where electricity is applied.
It is possible that at least one of the pair of electrodes is an electrode shaped in a positive image of the pattern. At this time, an anode shaped in a positive image of the pattern is preferably used. In the part other than the electrode shaped in a positive image of the pattern, no oxidized active species is formed, and decolorization, discoloration or change of color does not occur.
It is also possible upon applying electricity that an electro-nonconductive film or an electro-nonconductive spacer shaped in a negative image of the pattern is inserted between the electrode and the dyed fabric. At this time, the film or the spacer is preferably inserted between an anode and the dyed fabric. In this configuration, even when the electrodes are in a form of a simple plate, the pattern is formed by decolorization, discoloration or change of color caused by following the outer shape and the negative image of the pattern of the electro-nonconductive film or the electro-nonconductive spacer inserted between the electrode and the dyed fabric.
The invention is also an apparatus with the above-mentioned process for making pattern. Further, this invention relates to dyed fabric having a pattern and colored clothing having a pattern that are produced by the process.